1. Field of the Invention
This invention relates to a button feed unit which is disposed in a button feeder to guide a button element into a pocket disposed directly below a punch of a caulking unit after the button element and a rivet element are respectively delivered from individual chutes to the button feeder in a button applicator, and more particularly to a button feed unit which can be adapted in a button feeder to guide the button element and arrange the direction of surface pattern provided on the front face of the button element and which can be used widely for a variety of buttons of different sizes by exchangable components of constituting at least a feed path for the button element.
2. Description of the Prior Art
This kind of button feeders are disclosed in U.S. Pat. No. 5,031,815 and in Japanese Utility Model Publication No. H 3-12738 (1991).
The button feeder disclosed in U.S. Pat. No. 5,031,815 is composed of that a link pusher is rotatably attached to the tip of a swing lever pivoted to a frame and is reciprocated in a pusher guide trough defined in a button feed path to extrude and transfer a button element into a caulking unit of a button applicator. Then, a projecting portion is provided in the lower half part of the fore end of the pusher to place a part of the back face of the button element thereon and is always urged resiliently by means of a tension spring which is set between the swing lever and the pusher.
Further, the button feed path is defined in an unit composed of a metal square block and a web member having an L-shaped cross section. That is, a longitudinal trough is formed on the underside of the square block and has a wedge-shaped space for feeding the button body and a pusher guide trough. The wedge-shaped space is formed along the square block to contact the head surface of the button element with a receiving surface of the square block and to pinch a part of the front and back of the periphery of the button head. Further, a pressuring surface of the web member of the L-shaped cross section is disposed opposite to the receiving surface of the square block and is urged resiliently toward the receiving surface.
In this construction, when the button element having a tongue protruding from the rear face of the head is fed from the chute with its head surface facing downwardly into the button feed path of the feeder unit, a part of the button head is put on the projecting portion of the pusher, and at the same time, the pusher is advanced to extrude and transfer the button element. Then, since the head of the button element put in the wedge-shaped space has a larger slide resistance than the other part, the button element is transported while it rotates about its axis. This rotation is arrested as soon as the tongue of the button element is engaged in an engaging recess of the projecting portion of the pusher. Then, the button element is guided to the pocket of the caulking unit of the button applicator without rotation while the tongue is kept engaged in the engaging element. Accordingly, the button element transported to the caulking unit is arranged in a desired direction to provide a desired orientation of the surface pattern.
The button feeder for the button applicator disclosed in Japanese Utility Model Publication No. H 3-12738 comprises a guide base, a pressuring member of a substantially L-shaped cross section being urged resiliently downwardly perpendicular to the guide base, a wedge member being set between a pressuring surface of the pressuring member and the guide base and having a slanted surface, and a side guide member of a substantially L-shaped cross section being disposed opposite to the pressuring member and the wedge member and being urged resiliently toward each of the above individual members. In this case, the button feed path is defined by these members.
Further, when the button element is passed through the button feed path, the head of the button element with a large diameter is pinched between the wedge member and the pressuring member. Therefore, as the button head is transported in the button feed path from the chute to the caulking unit, one side of the button element has a larger friction coefficient than the other side thereof. Accordingly, when the button element is extruded by the pusher, it is transported while it rotates about its axis. Then, a finger is moved together with the pusher and a downward projection of the finger is engaged in the recess formed on the back face of the button head to orient and place a desired direction of the button element.
However, with the button feeder disclosed in U.S. Pat. No. 5,031,815, since the button feed path of the wedge-shaped cross section is formed directly in the square block, it is impossible to exchange the block with a new block. Furthermore, with the button feeder disclosed in Japanese Utility Model Publication No. H 3-12738, since the both pressuring member and side guide member are rotatably attached to the guide base by a pin, and at the same time, compression coil springs are set between the both members and the guide base, they can not be easily disassembled once they are assembled as the feed unit. As a result, the button feed unit is difficult to correspond with various button elements having a variety of diameters of heads. Accordingly, the button feeder can not be used widely for various buttons and button feed units as many as the number of the varieties of button elements are required if various button elements are used.
Further, with these button feeders, when a part of the button element is pressurized by the pressuring member, a portion of the button element put in the wedge-shaped groove is pushed by the slanted surface in the horizontal direction, and at the same time, the periphery of the button element put in the opposite groove is pinched resiliently between the upper and lower faces of the groove. Consequently, the button element can not be rotated smoothly due to reduced rotating force and thus can not be arranged in the desired direction surely as was expected.